There is no exploit as far as I know. It’s just something unusual I found while experimenting that I figured probably wasn’t intended to be possible.
Yeah, it occurred to me after I posted that the reason it might have allowed air into the mixing bowl was because it “typically moves down” as the tooltip for that fluid puts it, but I tried it with another heavier-than-air gas I had lying around (Fluorine) and it doesn’t go in.